Structure of baby walker

Abstract

A baby walker including a seat, an annular base frame, two pairs of wheels symmetrically mounted on the base frame, two links connected in parallel between the two pairs of wheels above the base frame, and two crossed supports connected between the links and the seat, wherein the base frame is comprised of an annular upper plate and an annular bottom plate; each wheel is comprised of a circular bottom shell fixedly coupled to the annular upper plate of the base frame and moved with it along the annular bottom plate of the base frame, and an upper shell pivoted to the circular bottom shell and having an arm pivoted to one end of one link.

What the invention claimed is: 
     
       1. A baby walker comprising a seat, an annular base frame, two pairs of wheel assemblies symmetrically mounted on said base frame, two links connected in parallel between said two pairs of wheel assemblies above said base frame, and two crossed supports connected between said links and said seat, wherein each of said wheel assemblies is comprised of a hemispherical upper shell, a circular bottom shell, a coupling member, and a dome-like cap, said upper shell comprising a center coupling barrel, and an arm perpendicularly extended from a periphery and terminating in a vertical axle housing, said coupling member and said dome-like cap being pivotably coupled to the axle housing of said arm by a screw bolt to hold one end of one of said links, each link having opposite ends pivotally coupled to the vertical axle housings of each pair of said wheel assemblies said coupling member having a bottom coupling section journalled in the vertical axle housing of said arm and a half-round notch at a top side thereof, said cap having a half-round notch matched with the half-round notch of said coupling member into a circular hole which receives one end of the corresponding link, said circular bottom shell comprising a center coupling barrel pivotably connected to the center coupling barrel of said upper shell by a screw bolt for permitting said upper shell to be turned relative to said bottom shell;   said annular base frame is comprised of an annular upper plate fixedly coupled to the bottom shells of said wheel assemblies, and an annular bottom plate coupled to the bottom shells of said wheel assemblies and imparting an annular track for permitting said wheel assemblies and said annular upper plate to be moved thereon through 360° angle, and rollers positioned between the bottom shell of each of said wheel assemblies and said annular bottom plate for permitting rolling movement therebetween.   
     
     
       2. The baby walker of claim 1 wherein the annular bottom plate of said annular base frame is comprised of a plurality of smoothly arched sections respectively connected to one another and coupled to the bottom shells of said wheel assemblies, each section of said annular bottom plate having a first coupling flange at one end, and a second coupling flange at an opposite end, said first coupling flange having a plurality of downward hooks, said second coupling flange having a plurality of retaining holes, the sections of said annular bottom plate being connected to one another by hooking the downward hooks of the first coupling flange of one section in the retaining holes of the second coupling flange of another. 
     
     
       3. The baby walker of claim 1 wherein the bottom shell of each of said wheel assemblies comprises two hooks bilaterally disposed on the inside, and two horizontal coupling holes disposed through the periphery at two opposite sides in alignment with the hooks; the annular upper plate of said annular base frame comprises a coupling lug at each end inserted into one horizontal coupling hole of the bottom shell of one wheel assembly and hooked on one hook of the bottom shell of the corresponding wheel assembly. 
     
     
       4. The baby walker of claim 1 wherein the bottom shell of each of said wheel assemblies has two bottom angle rails symmetrically bilaterally raised from a bottom side thereof, and coupled to the annular bottom plate of said annular base frame at two opposite sides. 
     
     
       5. The baby walker of claim 1 wherein the bottom shell of each of said wheel assemblies is equipped with two symmetrical pairs of equiangularly spaced rollers respectively supported on the annular bottom plate of said annular base frame.